Due to the flexibility provided by looseleaf binders, such binders and replacement sheets for these binders have become very popular for both school and business use. However, although looseleaf binders and looseleaf binder sheets have existed for many years, one problem that has remained unsolved is the inability of the looseleaf binder sheets to be both securely retained in the binder, while also being easily removed and subsequently reinserted without causing any ripping or tearing of the sheet of paper and without having to open the binder.
Although the desire to remove and replace individual sheets of paper in looseleaf binders without opening the binder and without tearing the edges of the sheet has always existed, the requirement that the looseleaf sheets be securely retained has been the dominant objective to which prior art patents have been directed. As a result, these prior art inventions and products teach reinforcing tabs, inserts, or liners, all of which are constructed to enhance the strength of the looseleaf sheet of paper in the area about the binder-receiving holes, in order to assure secure retention of the sheets by the binding posts or rings. Such systems are taught in U.S. Pat. Nos. 915,789 and 3,315,683. However, these prior art systems do not enable the user to remove any sheet from the binder without either opening the binder or ripping the sheet.
Consequently, the principal object of the present invention is to provide pre-punched sheets for looseleaf binders wherein each sheet is capable of being securely retained in the binder, free from accidental, unwanted dislodgement or removal, while also being freely removable from the binder without opening the binder and without permanently damaging the sheets of paper.
Another object of the present invention is to provide sheets of looseleaf paper having the characteristic features described above which is capable of being removed quickly and easily as well as repeatedly, without causing any degradation of the holding system.
Another object of the present invention is to provide sheets for looseleaf binders having the characteristic features described above which also incorporates edge reinforcements to further enhance the structural integrity and longevity of the dual-function sheets.
Other and more specific objects will in part be obvious and will in part appear hereinafter.